What is the challenge?

Truck fuel economy drops significantly as

speeds rise above 55 mph. Higher speeds can

also lead to higher engine maintenance costs

because engine life is directly related to the

amount of fuel burned over its lifetime.

What is the solution?

Trucks can improve fuel economy by reducing highway-driving speeds. Some motor

carriers have adopted a maximum speed policy for their drivers as a way to save fuel

costs and to promote safety. These policies can be implemented through electronic

engine controls, driver-training programs, or incentive programs that monitor truck

engine speed and reward drivers for staying within set limits. Nearly all new truck

engines in use today are electronically controlled and the cost of changing the

maximum speed settings on these engines is negligible.

The results are in...

The impact of vehicle speed on fuel economy depends on a range of factors, including

vehicle aerodynamics and operating patterns. Thus the specific impact of speed

reduction on fuel economy will vary significantly for each vehicle and speed range.

The American Trucking Associations (ATA) has estimated that a combination truck

driving 55 mph uses approximately 20-percent less fuel than a truck driving 65 mph.

Based on fuel economy data from the ATA and engine manufacturers:

• Reducing the maximum speed of a typical long-haul truck from 70 mph to 65 mph

would save over $1,450 in annual fuel costs.

• Reducing maximum speed further from 65 mph to 60 mph would save an

additional $1850 on fuel each year.

According to the ATA, the time between engine overhauls is directly related to the

amount of fuel consumed. Holding maximum speeds at 60 mph rather than 70 mph,

saves $135 per year on maintenance costs for a typical combination truck. These lower

speeds would eliminate more than 22 metric tonnes of carbon dioxide emissions in a

year for each truck.

Reducing the

maximum

speed of a

(typical) longhaul truck from

70 mph to 65

mph would

save over

$1,450 in

annual fuel

costs.

Green Transport Partnership

A Glance at Clean Freight Strategies:

Reducing Highway Speed

Office of Transportation and Air Quality • Mailcode? • October 2002 • EPA 420-F-02-021

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55 mph 65 mph 75 mph

Fuel Economy (mpg)
Reducing highway speed does mean longer travel times. A trucker driving at a

maximum speed of 60 mph instead of 65 mph would spend about eight percent more

time on the road. Because many drivers are paid by the mile or load, not by the hour,

reducing speed often does not directly increase trucking company labor costs. It may

reduce the productivity of trucking operations, however, because slower trucks are

able to carry fewer loads. Still, a number of well-managed fleets have found that the

benefits of speed reduction easily outweigh the costs.

Next steps

Trucking firms should examine the benefits of lower speeds and implement programs

to encourage drivers to reduce highway speeds. In most cases, the reduction in fuel

costs and maintenance far outweigh the increased delivery times. A number of wellmanaged truck fleets have programs in place to reduce highway speeds and promote

safe driving by using driver training, incentive programs, and electronic engine

controls. More information can be obtained from the following sources:

An Equipment Operating Costs Comparison. ATA Publication number T0006

Fleet Managers Guide to Fuel Economy, ATA Publication number T0013

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